1. RMSUpdate January 6, 2005 Retail Market Subcommittee Update to TAC

2. RMSUpdate Voting Items  Annual Validation Report to the ERCOT Board (Revised)  RMGRR 017 – Transaction Timing Matrix  RMGRR 016 – Oncor Name Change to TXU Electric Delivery Non-Voting Items  Load Research Sampling (LRS) Project Update Agenda

3. RMSUpdate  Annual Validation Report to the ERCOT Board (Revised)  Do not replace a prior year non-default assignment with a default assignment  Apply dead-bands around the specified Residential Segment trigger point  Apply a kWh minimum for Residential High Winter Ratio profile assignment  Review use of more stable Residential Winter Ratio formula.  RMGRR 017 – Transaction Timing Matrix  TITF initiative  Capture the modifications to Chapter 15  Minor editorial changes  RMGRR 016 – Oncor Name Change to TXU Electric Delivery  Name change only  All sections affected Voting Items

4. RMSUpdate Load Research Sampling (LRS) Project Summary As presented by ERCOT for RMS Meeting – 12/16/2004

5. RMSUpdate LRS Project Summary -- Project Background –Purpose: To collect load research data to support ERCOT’s load profiling efforts. The LRS data will be used to improve profiles and increase the accuracy of settlements. –ERCOT’s responsibility – to select the load research samples and make the Load Profile data available to market participants. –Sample locations were selected to distributed among each of 6 profile types and 8 weather zones. Profile Types = Residential Low Winter Ratio, Residential High Winter Ratio, Business No Demand, Business Low Load Factor, Business Medium Load Factor, Business High Load Factor Weather Zones = Coast, East, West, Far West, North, North Central, South, South Central –TDSPs responsibility – to install IDR meters for data collection; performing VEE on collected data; and transferring data to ERCOT

6. RMSUpdate 5 TDSPs MV90 CR ERCOT IDR NAESB EDM v1.6 HTTPS (FTP Replacement) CR IDR LRS Data Flow NOT USING EDI TRANSACTIONS

7. RMSUpdate LRS Project Summary -- Project Project Measurement and Metrics –Timeline Project start date – May 2003 Project Deployment date – November 2004 –ERCOT Budget Original Project Budget -- $1.5M Actual charges to date -- $700k (Not including TDSP expense) –(5) TDSPs Commitment All TDSPs completed Pilot testing Installed over 4200 IDR sample points Sample point readings have been transmitted to ERCOT starting in August 2004 –(13) CRs Commitment All CRs have completed Pilot testing ERCOT is in the process of building systems to transmit data to CRs

8. RMSUpdate LRS Project Summary Market Summary –TDSP Installation update as of 12/1/2004 –Ongoing ERCOT Responsibility Verify sample point installation and transaction confirmation underway Work with TDSPs on remaining installations and replacements (on-going) Transition to O&M role for sample point management and tracking Provide data to Market Participants as required CompanyInstalled AEP North366 AEP Central581 Centerpoint423 TXU Electric Delivery2765 TNMP105 Sharyland1 Total4241 Complete to Date96.56%

9. RMSUpdate ??? Questions ???

10. RMSUpdate Voting Items PWG Action Plans 1. Do not replace a prior year non-default assignment with a default assignment  A new calculation for each ESI ID is made each year  Currently: Insufficient data requires assignment to default  Residential defaults to Residential Low Winter Ratio (RESLOWR)  Commercial defaults to Business Medium Load Factor (BUSMEDLF)  Proposed: If sufficient data was available in a previous year an assignment to default would not be made

11. RMSUpdate Voting Items PWG Action Plans 2. Applying dead-bands around the specified Residential Segment trigger point  Currently : If WR > 1.5 it is assigned to High Winter Ratio (HiWR)  Proposed : Create a dead-band around the 1.5 trigger point  Example – Assume dead-band (1.0 to 2.0) if current assignment is RESLOWR and new WR = 1.7, would remain RESLOWR if current assignment is RESLOWR and new WR = 2.1, would change to RESHIWR  Result - significant reduction in migration

12. RMSUpdate Voting Items PWG Action Plans 3. Use more than 1 month for the Residential Winter Ratio formula  Example – Change numerator to average the ADU for highest 2 months  Result - significant reduction in migration

13. RMSUpdate Voting Items PWG Action Plans 4. Apply a kWh minimum for Residential High Winter Ratio profile assignment  Currently: None  Proposed: Identify a reasonable minimum usage for High Winter Ratio assignment  Example – RESHIWR minimum = 10 kWh/day (300kWH/month) If WR = 3.0 and 5 kWh/day then assign RESLOWR If WR = 3.0 and 15 kWh/day then assign RESHIWR

14. RMSUpdate Voting Items PWG Action Plans 5. Use an ERCOT administered residential survey to determine heating system type for a sample of customers  The survey will empirically support data used to define dead- bands, minimum thresholds and revised WR calculation  40,000 surveys will be mailed to end use customers  5,000 to each weather zone  2,500 to each existing profile type current assignment